Ask for help, why can't this append display?

this is a todolist js code. Want to know why the append here is not available
here is all the current code link description

;(function () {
    "use strict";
    var $submit_task = $(".submit-task")
    , task_list ={}
    ;
    
    

    init();

    $submit_task.on("click",function(e){
        var new_task = {};
        // 
        e.preventDefault();
        // task
        new_task.content= $(this).prev(find("input[name=content]")).val();
        // task  
        if(!new_task.content) return ;
        // task
        if(add_task(new_task)){
            render_task_list();
        }
    })

    function add_task(new_task){
        //tasktasklist
        task_list.push(new_task);
        // localStorage
        store.set("task_list",task_list);
        console.log("task_list",task_list);
    }

    function init(){
        task_list = store.get(".task-list")||[];
        if(task_list.length)
            render_task_list();
    }

    function render_task_list(){
        var $task_list= $(".task-list");
        $task_list.html("");
        for( var i = 0 ; i < task_list.length ; iPP)
        {
             var $task = render_task_tpl(task_list[i]);
             $task_list.append($task);
        }
    }

    function render_task_tpl(data){
        var list_item_tpl = 
                            "<div class="task-item">"+
                            "<span><input type="checkbox"></span>"+
                            "<span class="task-content">"+data.content+"</span>"+
                            "<span class="action"> </span>"+
                            "<span class="action"> </span>"+
                            "</div>";
        return $(list_item_tpl);
    }
})();
Sep.08,2021

task_list initializes an empty object at first, and then operates on an array all the time.


task_list initialization is an object, followed by an array of

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